vanEssen CTD-Diver DI28 Series User manual

CTD-Diver® DI28x Series

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Essen Instruments B.V.
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logo, Diver and CTD-Diver are trademarks or registeredtrademarks ofVanEssenInstrumentsB.V.
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CE COMPLIANCE STATEMENT (EUROPE)
We hereby declare thatthedevice(s) describedbelow arein conformity with thedirectives listed.In
theeventofunauthorizedmodification of anydevices listedbelow, thisdeclarationbecomes invalid.
Type: Datalogger
ProductModel: CTD-Diver(DI281, DI282,DI283, DI284)
Relevant EC Directives and Harmonized Standards:
1999/5/EC R&TTE Directive for Radio andTelecommunications Terminal Equipment in accordance to
annexIII to which thisdirective conform to thefollowingstandards:
Low Voltage Directive per EN60950-1 (2006)+A11 (2011) forProduct Safety testing
standardfor"InformationTechnology Equipment"
EMC Directive EN 301 489-1 V1.8.1 / EN 301 489-17 V1.3.2 Electromagnetic emissionand
immunityfor"InformationTechnology Equipment"
2014/30/EU Electromagnetic Compatibility directive, as amended by EN61326-1:2013
Theproduct(s) to whichthisdeclaration relatesisinconformity withtheessential protection
requirements of 2014/30/EU Electromagnetic Compatibility directive. The products are inconformity
with thefollowing standards and/orother normative documents:
EMC: Harmonized Standards: EN 61326-1:2013 Lab Equipment, EMC
IEC61000-6-3:2007 Emission standard forresidential, commercialand light-industrial
environments
IEC61000-4-2:2009 Electrostatic dischargeimmunity test
IEC61000-4-3:2006 Radiated, radio-frequency, electromagnetic field immunity test
IEC61000-4-4:2012 Electrical fast transient/burst immunity test
IEC61000-4-5:2006 Surge immunity test
IEC61000-4-6: 2014 Immunity to conducted disturbances, induced byradio-frequency fields
IEC61000-4-11:2004 Voltage dips, short interruptions and voltage variations immunity tests
I hereby declarethat the equipment namedabove has been designedto comply withthe relevant
sections oftheabove referenced specifications. Theitems comply withall applicable Essential
Requirements of the Directives.

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Contents
1Introduction.........................................................................................................................................1
Aboutthis Manual ......................................................................................................................1
OperatingPrinciple....................................................................................................................1
MeasuringWater Level...............................................................................................................2
Measuring Temperature.............................................................................................................4
MeasuringConductivity .............................................................................................................4
CTD-Diver Model.........................................................................................................................6
Factory Calibration Procedure...................................................................................................6
2TechnicalSpecification .......................................................................................................................7
General .......................................................................................................................................7
Environmental............................................................................................................................8
Transportation ...........................................................................................................................8
Temperature...............................................................................................................................8
Pressure......................................................................................................................................9
Conductivity.............................................................................................................................10
SampleIntervaland Methods..................................................................................................10
3CTD-DiverInstallationandMaintenance..........................................................................................13
Introduction .............................................................................................................................13
Configuring and Readingthe CTD-Diver..................................................................................13
Installation ina MonitoringWell..............................................................................................16
Installation in Surface Water....................................................................................................16
Use of CTD-Divers at Varying Elevation...................................................................................17
UseinSeawater........................................................................................................................17
Biofouling.................................................................................................................................17
CTD-Diver Maintenance ...........................................................................................................17
User Conductivity Calibration..................................................................................................17
4AppendixI Use of CTD-Divers at VaryingElevations......................................................................20
5AppendixII CTD-Diver CommunicationProtocol...........................................................................21
Introduction .............................................................................................................................21
SerialPort Settings...................................................................................................................21
FrameFormat...........................................................................................................................21
List of Commands ....................................................................................................................22
6AppendixIII CTD-Diver Accessories................................................................................................27
Diver-Office software ...............................................................................................................27
USBReadingUnit.....................................................................................................................27
Stainless Steel Cable................................................................................................................27
Cable Clip..................................................................................................................................28
DiverCopper Shield..................................................................................................................28
Smart InterfaceCable ..............................................................................................................28
Communication Cable .............................................................................................................29
Diver-Mate ................................................................................................................................29
Diver-Link .................................................................................................................................30

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1
1Introduction
The CTD-Diver® isa compact, groundwatermonitoring instrument for continuously measuring level,
temperature and electrical conductivity in groundwater, surface water, and industrial waters.The
data collected canbe used to manage water resources, estimate hydraulic conductivity and other
aquifer conditions. Examples of applications are:
•monitor potable waterrecharge areas for watersupply,
•monitor tailings ponds,dewatering activities and water supply levelsof mines,
•general site investigations for construction, and
•contaminant plume monitoring on spill sites, remediation sites, chemical storage facilities,
landfillsitesandhazardouswaste storagesites.
The CTD-Diver is an easy-to-usedatalogger featuringstate-of-the-art electronics ,a robust high
precision pressure sensor for long term accuracy and a platinum 4-electrode conductivity sensor. The
absolutepressure sensor requires minimalmaintenanceandre-calibration.
The CTD-Diver is a datalogger housed ina cylindrical casing with a suspension eye at the top.The
suspension eye can be unscrewed and is designedtoinstall the CTD-Diver intothemonitoringwell.
Thesuspension eye also protects the opticalconnector. Theelectronics, sensorsandbattery are
installed maintenance-free into thecasing. The CTD-Diver is notdesignedtobe opened.
The name ofthe datalogger, the model number, the measurement range and the serial number are
identified on the sideof the CTD-Diver. This information is etched usinga laser and is consequently
chemically neutral and not erasable.
AboutthisManual
Thismanualcontains information aboutVan Essen Instruments CTD-Diver withpart number DI28x,
seesection 2.5, an instrument designed tomeasure groundwater levels, temperature and electrical
conductivity.
Thischapter containsabriefintroduction tothe CTD- 2
contains thetechnical specifications for the CTD-Diver as wellasguidelines for Divermaintenance.
Chapter3 covers the deployment of Divers. This includes programming the Diver with the Diver-Office
software. Subsequently, installation of Divers inmonitoring wells and in surface water is discussed.
There are threeappendices that describetheuse ofDivers at varyingelevation, theDiver
communication protocol and a list of CTD-Diver accessories.
OperatingPrinciple
The CTD-Diver is a datalogger designed tomeasure water pressure, temperature and conductivity.
Measurements are subsequently stored in the CTD-Diver's internal memory. The CTD-Diver consists of
a pressure sensor designed to measurewater pressure, atemperature sensor, a 4-electrode
conductivity sensor and a battery that powers theelectronics that takes and stores the
measurements. TheCTD-Diver isanautonomous dataloggerthat canbe programmedby theuser. The
CTD-Diver has a completely sealed inert ceramic enclosure. The communication between CTD-Divers
andLaptops/field devicesisbasedonoptical communication.
The CTD-Diver measures the absolute pressure. This means that the pressuresensor not only
measures thewater pressure, but alsothe air pressure pushing onthewater surface. Ifthe air
pressurevaries, the measured water pressurewillthus alsovary, withoutvarying the waterlevel. The

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2
air pressure canbe measured by a Baro-Diver and subsequently be usedin theDiver-Office software
to convert the CTD-Diver pressure readings intowater level data.
MeasuringWaterLevel
The CTD-Diver establishes theheight of a watercolumn by measuringthewater pressure usingthe
built-inpressure sensor. As long as theCTD-Diver isnotsubmerged inwateritmeasures atmospheric
pressure: thehigher thewater column thehigher themeasured pressure. The height of thewater
column above theDiver's pressure sensor isdetermined based on themeasured pressure.
Tomeasurethese variationsin atmosphericpressure a Baro-Diverisinstalled for eachsite being
measured. The barometric compensation for these variations in atmospheric pressure can be done
usingtheDiver-Officesoftware, seewww.vanessen.com fora free download.It is also possibletouse
alternativebarometric datasuchas datamadeavailableonline.
The barometrically adjusted water values can be related to a reference point such as the topofthe
monitoring well or Mean Sea Level (MSL) orany other verticalreference datum.
1.3.1 ConvertingDiverDataintoWater Level
This section explains howto calculate the water level in relationto avertical reference datum using
theCTD-Diver and Baro-
The figurebelow represents an example ofa monitoring well inwhich a CTD-Diver has been installed.
In this casewe are therefore interestedin the height ofthe water level(WL) in relationto the vertical
reference datum. If thewater level is situated abovethe reference datum ithas apositive valueanda
negative value ifitis situated below thereference datum.
Thetopofcasing(TOC) is measuredinrelation to the vertical reference datumandis denoted inthe
diagram below asTOC. The CTD-Diver is suspended witha cable with alength CL. If thecable length is
not exactly known, it canbe calculated from a manual measurement as described in section 1.3.2.
TheBaro-Diver measuresthe atmosphericpressure (pbaro) and the CTD-Diver measures the pressure
exerted by thewater column (WC) above the CTD-Diver and theatmospheric pressure (pDiver).

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The watercolumn (WC) abovethe CTD-Diver can beexpressed as:
   
 (1)
wherepisthepressure incmH2O, g istheaccelerationdue togravity (9.80665 m/s2) and ρisthe
densityofthewater (1,000kg/m3).
Thewaterlevel (WL) in relation to the verticalreference datumcanbe calculatedasfollows:
     (2)
BysubstitutingWC from equation(1)inequation (2) we obtain:
     
 (3)
1.3.2 CalculatingtheCableLengthfromaManualMeasurement
If thecable length is not exactly known,it can bedetermined using a manualmeasurement, see the
figurebelow. The manual measurement(MM)istaken fromthetopofcasing to thewater level. The
value ofthe water levelis positive unless, in exceptional circumstances, the water level issituated
above thetop ofcasing.
Thecablelength can nowbecalculatedas follows:
     (4)
where thewater column (WC)iscalculated based onthe measurements takenbythe CTD-Diver and
theBaro-Diver.
Notes:
•If the pressuremeasured by the CTD-Diver and the Baro-Diver is measured at different points
intime,itisnecessary to interpolate. The Diver-Office software automatically performs this
interpolation.
•It is possibleto enter manual measurements into the Diver-Office software. The software
subsequently automaticallycalculates thecable length.
Example
The top ofcasing is measured to be150cm above the Mean Seal Level(MSL): TOC =150 cm.
The cable length is not exactly known and therefore amanual measurement is taken. It turns
out tobe 120 cm: MM= 120 cm.

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The CTD-Diver measures a pressure of1,170 cmH2Oand theBaro-Diver measuresa pressure
of1,030cmH2O. Substituting these values into equation (1), results in a watercolumn of 140
cm above the Diver: WC = 140 cm.
Substituting thevalues ofthe manual measurement and thewater columninequation (4)
results in thefollowing cable length: CL =120 +140 = 260cm.
The water level inrelation to MSL can nowbe easily calculated using equation (2):WL = 150
260 +140 =30 cm above MSL.
MeasuringTemperature
AllDivers measure the groundwater temperature. This can,for example, provideinformation about
groundwater flows.
Thetemperature is measured usinga semiconductor sensor. Thissensor notonly measures the
temperature, butalso usesthevalueofthe temperatureat thesametimeto compensate the pressure
sensor andelectronics for theeffects of temperature to ensurethe bestpossible performance.
MeasuringConductivity
Inadditionto water levels andtemperature, theCTD-
conductivity inmilli Siemensper centimeter(mS/cm). A changeinconductivity may becausedby for
examplechanges in water floworincreasing/decreasing pollutionor salinization.
The conductivity is measured usinga 4-electrode measuring cell. This type of measuring cell is
relatively insensitivetosensor fouling, thus keeping maintenancetoaminimum. Themeasuring cell
combined withthe selected measurementmethodresults inanelectrolysis-free measurement system.
The CTD-Diver measures the conductivity of a solution. The CTD-Diver can be programmed to
measureeitherthe true conductivity orthespecificconductivity.Thespecific conductivity is defined
as the conductivity as if the temperature is 25 °C. This setting must beprogrammed prior to starting
the CTD-Diver.
The conductivity of aliquid depends onthe type ofions inthe liquid and to asignificant degree on the
Thisdependency is indicated on thepackaging ofthe calibration solution. The
diagrambelow displays theconductivity as a functionoftemperature for threedifferentcalibration
liquids. The specified valueof the calibration liquid isthe conductivity of theliquid at 25 C.

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Asa ruleof thumb,itcanbeassumed thatconductivity variesby2%foreach 1 Cchange in
temperature. This means that a calibration solution rated 5 mS/cm (at 25 C)has a conductivity of
approximately 4mS/cm at15 C.
The tablebelow lists several typicalconductivity values for various typesof water.
Type
Conductivity [mS/cm]
Tap water
0.2 0.7
Groundwater
2-20
Seawater
50-80
1.5.1 SpecificConductivity
Thespecific conductivity ofan electrolytesolution isdefined asthe conductivity ifthe solutionisata
certain reference temperature.The specific conductivity is an indirectmeasure of thepresence of
dissolvedsolids such as chloride,nitrate, phosphate,and iron,andcanbeused asanindicator of
waterpollution.
The followingequation isused forcalculating thespecific conductivity KTref fromthemeasured
conductivity K.
  
󰇛󰇜  (5)
where:
KTref = Specific conductivity at Tref
K = Conductivity at T
Tref = Reference temperature (25 °C)
T =Sample temperature
θ=Temperaturecoefficient(1.91 %/°C)

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Thetemperature coefficient used intheCTD-Diver is1.91 %/°C andthe reference temperature is 25°C.
Thesettingto measure conductivityor specific conductivity canbeprogrammed into theCTD-Diver
bytheuser.
CTD-DiverModel
The Diver models described inthis manual are from the DI28x Series: the CTD-Diver.TheCTD-Diver
measuresabsolute pressure, temperature and conductivity.
CTD-Diver
This Diveris manufactured using a zirconia (ZrO2) casing with a22mm
diameter. The CTD-Diver canstore a maximum of144,000
measurements (date/time,pressure, temperature and conductivity)in
itsworking memory and 144,000 measurements initsbackupmemory.
The CTD-Diversamples pressure, temperature and conductivity and has
the followingmeasurement options:
•Fixed length intervals in fixed length or continuous memory.
•Average values.
•Pre-programmed or user-defined pump tests.
•Event-based. The CTD-Diver only storesmeasurements once
theuser-adjustable variation limit setfortheconductivity
measurement is exceeded.
The CTD-Diver isavailable in the following pressureranges: 10 m, 50 m,
100 mand 200m.
FactoryCalibrationProcedure
EachCTD-Diver is calibrated for pressure,temperatureand conductivity:
1. FirsttheCTD-Diver isindividually calibratedandtested at severaltemperatureandpressure
values toensure superiorperformance. The CTD-Diver is calibrated forthe lifetime of the
instrument, as long as itis usedwithinitsspecified range.
2. Then the conductivity sensor is individually calibrated and tested at several conductivity
values. Thefactory calibration is storedpermanently in theCTD-Diver.
A calibration certificate isavailable upon request.

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2TechnicalSpecification
General
Therearefour CTD-Diver models with different pressure ranges for pressure,temperature and
conductivity measurements. The table below lists the general specifications of the CTD-Diver.
Diameter
Ø 22mm
Length(incl.suspension
eye)
~135mm
Weight
~95grams
Materials
Casing
Ceramic(zirconia ZrO2)
Pressure sensor
Piezoresistive ceramic(aluminaAl2O3)
Conductivity sensor
4-electrode withplatinum electrodes
Suspension eye
nosecone
NylonPA6glass fiberreinforced (30%)
ABS
O-rings
Viton®
Communication
Interface
Optically separated
Protocol
Serial RS232, a limited set of commands is available as specified inAppendix
II
Memory capacity
288,000 measurements
working
144,000 measurements
backup
144,000 measurements
Memory
Non-volatilememory.Ameasurement consistsofdate/time, pressure,
temperature, and conductivity
Continuous and fixedlength memory
Batterylife*
Upto 10 years, dependingon use
Theoretical battery
capacity
2 millionmeasurements + 1000× full memory readouts +
2000× programming
Clockaccuracy
Better than ±1 minute per year at 25 C
Better than ± 5minutes per year withinthe operating temperature range
CE marking
EMCinaccordance withthe89/336/EEC directive
Basic EN 61000-4-2 standard
Emissions
EN 55022 (1998) +A1 (2000) + A2 (2003), Class B
Immunity
EN 55024 (1998) +A1 (2000) + A2 (2003)

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*The CTD-Diver is always in stand-by when not making a measurement. The power consumption
of theintegrated batteryisdependent onthe temperature and usage.
If theCTD-Diver isused, stored ortransported for extended periods of time under high temperature,
reduced, butthis isnot permanent. This is normal behavior for batteries.
Excessive programming, high frequency sampling and data reading will reduce thebattery capacity.
**Theaccuracy of the clockis highly dependentontemperature. Theclock is actively compensated
for temperature variations.
Environmental
Ingress protection IP68, 10years continuously submerged in water at 200m
Transportation
Suitablefortransportationby vehicles, shipsandairplanes inthesupplied packaging.
Resistancetovibration Inaccordancewith MIL-STD-810.
Mechanical shock test In accordance with MIL-STD-810, for light-weight equipment
Temperature -20°C to80 °C(affects batterylife)
Temperature
Measurement range
-20°Cto80 °C
Operating Temperature (OT)
0°Cto50 °C
Accuracy (max)
±0.2°C
Accuracy(typical)
±0.1°C
Resolution
0.01°C
Response time(90%offinal value)
3 minutes(inwater)

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Pressure
Thespecifications forwater pressuremeasurementsvary by CTD-Divermodel. Thespecifications
below applyat operating temperature.
DI281
DI282
DI283
DI284
Unit
Water columnmeasurement range
10
50
100
200
mH2O
Accuracy (max)
±2.0
±10.0
±20.0
±40.0
cmH2O
Accuracy(typical)
±0.5
±2.5
±5.0
±10.0
cmH2O
Long-term stability
±2
±10
±20
±40
cmH2O
Resolution
0.2
1
2
4
cmH2O
Displayresolution
0.058
0.192
0.358
0.716
cmH2O
Overload pressure
15
75
150
300
mH2O
2.5.1 WaterColumnMeasurementRange
Theheight ofwater abovethe CTD-Diverthat canbe measured.
2.5.2 Accuracy(maximum)
Accuracy is theproximity ofmeasurementresults tothetrue value. Thealgebraic sumofalltheerrors
that influence the pressure measurement. These errorsare due to linearity, hysteresisand
repeatability. During the CTD-Diver calibration process a CTD-Diver is rejected ifthe difference
betweenthemeasured pressureandtheapplied pressureislargerthanthe statedaccuracy.
2.5.3 Accuracy (typical)
At least 68%of the measurements during the calibration check are within 0.05% FSof the
measurement range.
2.5.4 Long-termStability
Thestability of the measurement over a periodoftime when a constantpressure isapplied at a
constant temperature.
2.5.5 Resolution
The smallest change in pressure thatproduces a response in the CTD-Diver measurement.
2.5.6 DisplayResolution
The smallest increment inpressure that the CTD-Diver can measure.
2.5.7 OverloadPressure
The pressure at whichthe CTD-Diver pressure sensor will catastrophically fail.

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Conductivity
Measurement range*
30 mS/cm
120 mS/cm
300 mS/cm
Accuracy**
±2% ofreading witha minimum of 20S/cm
Resolution
1S/cm
4S/cm
10S/cm
*User adjustable
** Undefined when reading> 120mS/cm
SampleIntervalandMethods
Theminimumand maximumsampleinterval plusthevarioussample methodsavailable forthe CTD-
Diver are listed below.
Sample interval
1 secto99hours
Sample methods
•Fixed length intervals in fixed length or continuous (ring)
memory.
•Averagevalues over a specifiedperiod.
•Pre-programmed pump tests or user-defined pumptests (no
backupmemory).
•Event-based.Inthis case the CTD-Diveronlystores
measurements once the variationlimit set fortheconductivity
measurement is exceeded. This variation limit is user
adjustable(no backup memory).
2.7.1 Fixed
When this method is selected, the CTD-Diver will take andstore samplesin regulartime intervals.
For example,witha 10-second fixedrecordinterval, the CTD-Diverwilltake ameasurement every10
secondson all channelsettings and thenstorethesevalues ininternal memory, withthe date and
time.
FortheCTD-Diver therearetwomethods forstoringdata:
•Fixed Length Memory The CTD-Diver will take measurements at a sampleinterval set by the
user, forexampleevery hour. Whenthe numberofsamples reaches 144,000,i.e. the memory
isfull,the CTD-Diverstops measuring.
•Continuous Memory The CTD-Diver will takemeasurements at a preset sampleinterval
data. When thememory fills up, newsamples beginoverwriting the oldestrecords.
2.7.2 Averaging
When programmed with the Averaging Samplemethod, the CTD-Diver samples data at a specified
of these values at thespecified averaging rate
(Record Interval).
Example
Record Interval:1hour
Sample Interval: 1Minute

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Whenprogrammed andstartedwith thesesettings,the CTD-Diverwill reada sampleevery
minute,andrecord an average of the samplesevery 1 hour.
Forsurfacewater applications it is recommendedusing theaveragingsamplingmethod. This
way t
2.7.3 Event Based
When you select this method, the CTD-Diver compares each conductivity sample to the last stored
conductivity sampleandcalculatesa difference. Anewsample is only storedwhen:
•The difference exceeds the specified difference (percentage) from the last stored sample on
theconductivity measurement.
•Ifnosampleswere storedforthepast250samples.
Ifyouselectthis method,the Variation fieldwillbe displayed. IntheVariation field, specifythe
appropriate difference threshold. Enter this difference asa percentage of thetotal conductivity range.
Thepercentage must liebetween0.1% and 25%.
Example
The conductivity range isset to 120 mS/cm, the Variation field is setto 2%and thesample
interval is setto 30 seconds. A new sample will be stored whenit deviates more than 120 × 2%
=2.4mS/cm fromthepreviouslystored sample.
The CTD-Diver is started at 12:00:00. Itwillimmediately recorda sample (pressure,
temperature and conductivity). The recorded conductivity is 23mS/cm. After30seconds, the
CTD-Divertakes anewsample: theconductivity is 23.5mS/cm.Thissample will notbe
recorded,because the difference is 0.5 mS/cm,which is less than2.4 mS/cm.
Also,forthenext 249samples thedifferenceislessthan 2.4mS/cm,so nosamplesare
recorded.However, whenthe250th sample istaken, itis recorded (at 14:05:00) regardless the
difference.
2.7.4 PumpingTests
The CTD-Diver can be programmed with apumping test logging scheme. Generally, the logging
intervalisshort at the start andincreaseswhen the pumpingtests progresses.
Thereare two pre-programmed pumpingtests availablefor theCTD-Diver. Theseareas listed in the
two tables below. Inaddition, user-defined pumping tests can be programmed in theCTD-Diver.
A pumping testis defined by a basesample interval (from 1 second to 99hours) and up to 10 different
logging steps. Foreach step the number of samples thatmustbe takenmust beset plus the Interval
Multiplier (1 to 250). The interval between twosuccessive samples is equal to the Base Sample
Interval multipliedby the Interval Multiplier. Forexample, if the Base Sample Interval is 3seconds
andtheInterval Multiplier is 5, then thesampling interval is 15 seconds. Note: The Base Sample
Interval is equalfor all steps.

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Aquifer Log Scale Test - 3 Day
Base Sample Interval: 1 second
Step
Number of
samples
Interval
multiplier
Interval between
samples
Duration
1
600
1
1 seconds
10minutes
2
1080
5
5 seconds
90minutes
3
5400
10
10seconds
15 hours
4
136920
30
30seconds
47 days
Aquifer Log Scale Test - 2 Month
Base Sample Interval: 5 seconds
Step
Number of
samples
Interval
multiplier
Interval between
samples
Duration
1
120
1
5 seconds
10minutes
2
270
4
20 seconds
90minutes
3
900
12
60 seconds
15hours
4
1800
60
5 minutes
150hours
5
140910
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3CTD-DiverInstallationandMaintenance
Introduction
In practicethe CTD-Diver is suspended in amonitoring well and the Baro-Diverisinstalled at the
surface for recording barometric pressure. Atmospheric pressure data mustbe used to compensate
thepressure measurementsrecorded bythe CTD-Diver forvariations in atmospheric pressure.In
principle, a singleBaro-Diver is sufficient foran area with a radius of15 kilometers depending on
terrain conditions. Also see AppendixI UseofCTD-Divers at VaryingElevations.A10-meter changein
elevation is the equivalentof a barometric pressure change of approx.1cmH2O or 1mbar.
Thefollowing sections describe how toinstall the CTD-Diver andBaro-Diver.
ConfiguringandReadingtheCTD-Diver
A CTD-Diver must beprogrammed withthedesired samplemethod, sample interval, andmonitoring
pointnamebefore itisdeployed.The CTD-Diver can be programmed, started, stopped andits data
read using theDiver-Office software. The latest version of Diver-Office can be downloaded for free
fromwww.vanessen.com. Once thesoftware isinstalled, a CTD-Diver canbeconnected tothe
computer through a USBReading Unit (part no AS330), a Smart Interface Cable (part no. AS346)or the
Diver-Gate(M) (part no.AS345).
3.2.1 Configuringa CTD-Diver
Open the Diver-Office software and clickthe Diver buttontoopentheDiverwindow.See the image
below for anexample where the following settings were entered:
•-3
•Fixed Fixed- ,
•record interval: 1 hour,
•conductivity range: 120mS/cm,
•conductivity type: specific conductivity.
After entering the settings, the Diver must beprogrammed by clicking the Program button.
Theconductivity rangecanbesetto30, 120 or300mS/cm. Select therangecorrespondingto the
expected measurement values. A higherrange reduces theresolution ofthemeasurements. When the
actual measurement value exceeds the conductivity range, then stored value is clipped to the
maximum value.
Settheconductivity typetothedesired type.Seesection 1.5.1SpecificConductivity formore details.

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Oncethesettings aresuccessfullyprogrammedinto the CTD-Diver theStart button will be enabled.
ClickingtheStart button opens the Start Diver dialog as shownbelow. Here youcan select fromthe
following three startmethods:
•Immediate Start - Select this optionto start the CTD-Diver immediately. Upon clicking
[Start], the Diver willbegin totake andrecord samples, as definedin the CTD-Diver settings
•FutureStart - Selectthisoption to startthe CTD-Diverat a specifiedtimeinthefuture.Use
thedateand time boxesto enterthedesired future starttime.
•Smart Future Start - Thisoption is useful in situations where you want tostop the CTD-Diver,
download its data and thencontinue collectingdata at the specifiedsampleinterval.
After selecting thedesired start method, click the [Start] button to save thestart settings to the CTD-
Diver.

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3.2.2 Reading Data froma CTD-Diver
ClicktheData button to download data from the CTD-Diver. Click the downarrow next to the Data
button tochange the mode/type ofdata download:
Depending on thesample interval thefollowing 3options are available:
•Data - downloadall the data recorded bytheDiver.
•NewData - downloadonlynewly recordeddata(since the last data download).This option is
notavailable whenthesample intervalis5seconds orless.
•Backup Data - download data from theprevious monitoring session.
Duringthedata downloadthe progressisindicated by a progress bar. Oncethedatahas been
downloadeditwill be exported if this optionisselected intheProject Settings. Subsequently, the
program will jump tothe tree view where the downloaded time series will beselected and a
graph/table ofthe datawillbe shown.

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16
InstallationinaMonitoringWell
CTD-Divers arenormally installed below thewater
level/tablein a monitoringwell. The depthatwhicha
CTD-Divercan be suspended dependsonthe instru
measurement range. Further information aboutthe CTD-
range iscontained in the chapter 2 Technical
Specification.
First determine the length of thenon-stretch suspension
cable (part no MO500) based on thelowest groundwater
level.Provide for the required additionallengthfor
attachingthecable to thesuspensioneyeof the Diverand
attheupper endwhenyou cutthewiretosize.
Next use cableclips (part no MO310) to attach theends of
thecableto
To determine the distance of thepressure sensor in the
monitoring well requires thepreciselength ofthecable to
beknown, to which the distanceto the locationofthe
pressure sensor inthe Diver must beadded to obtain the
overall effective cablelength. Thisisdepicted inthe
diagram below.
It is alsopossible toinstall the CTD-Diver with a
communication cable (part no AS2xxx). This cable allows
youtoreadoutthe CTD-Diver atthetop ofthe monitoring well byusinga Smart Interface Cable(part
noAS346).
Note thatin smalldiameter wells theinstallation andremoval of the CTD-Diver may affectthe water
level.
InstallationinSurfaceWater
IfaCTD-Diver is usedinsurface water, it is important that
there is sufficient circulation around the CTD- s sensors.
Sedimentation, algae andplant growth shouldbeminimized
as much as possibleto ensure the CTD-Diver measures the
surrounding water level.
Position the CTD-Divers deep enough so that they remain
below a possible ice layer.
A steel protective cover that canbe locked should be used to
prevent vandalism or theft of the CTD-Diver.
CTD-Diverscan also beusedto indirectly measure discharge.
Insuchacase, the CTD-Diver can be installed in a monitoring
tube/screennext to a weir.